The principle of the method is applied industrially for the continuous treatment of liquid waste products containing mineral fillers, this treatment being carried out by wet-route oxidation. It is described in international publication WO 2010/108290 A1.
Solid organic waste products that may contain mineral substances and which pose a hazard to health, notably when the said waste products are radioactive, have to be handled with special precautions in order to avoid their dispersion, starting from the phase when the wastes are brought to a treatment site, throughout every stage of the treatment, and until their disposal after treatment. It has been found that these precautions cannot be taken when the treatment is carried out continuously, i.e. when the materials to be treated are brought to a relatively open site which does not offer the requisite guarantees of environmental security. In effect, when the site is open so as to allow the continuous supply of the materials to be treated, the risk that hazardous residues in the form of fine particles, gaseous substances or even in liquid form may leak out cannot be totally eliminated.
U.S. Pat. No. 6,090,291 describes a treatment method for the decomposition of organic or inorganic materials in a plant that maintains them in a state said to be “supercritical”, i.e. in which the treatment water is at temperatures above 374° C. under a pressure in excess of 318 bars. Such a technology has fundamental differences compared with the method of the present invention, these differences including the high cost of the plant, the management of risks that are much more complex, the cost of the treatment, notably because of the treatment temperatures which are higher, entailing higher heating costs. The supercritical and subcritical states are fundamentally different and it is not obvious, even to a person with knowledge of the field, to carry out the treatment of hazardous substances by a process of oxidation treatment while keeping the said substances in an aqueous medium which is in a subcritical state. It is also impossible to deduce from a technology that uses a method for the treatment of organic or inorganic substances in a supercritical state, the knowledge required for carrying out the treatment of hazardous substances by oxidation While maintaining them in a subcritical state.
Because of this, the knowledge of the prior art does not deprive the invention of novelty and does not constitute a basis sufficient, for a person familiar with the field, to deprive the invention of inventiveness. The invention does not follow in any evident manner from the prior art, which describes a fundamentally different technology.